I've been a happy WordPress customer for over two years, but a recent problem is really making it frustrating to use. Sometimes, when I want to save a post I've just written, or update an old one, WordPress hangs and won't update, meaning I have to lose my post (saving the text elsewhere, of course) or leave it as it is. The screen doesn't lock, but the post won't save. I've tried the same posts with different browsers (Firefox, Explorer, Chrome), but it's always the same.
Does anybody recognise this problem? Is it likely that I've made a change somewhere that is causing it?
The blog I need help with is drnorth.wordpress.com.